SIP-based user mobility providing apparatus and method

ABSTRACT

Disclosed are an SIP-based user mobility service providing apparatus and method using user position information obtained by a sensing apparatus. When a user enters a specific region, a gateway including a sensing management module carries out SIP registration for several terminals existing in the specific region in place of user agents of the terminals. The sensing management module transmits an SIP registration message to an SIP proxy server and notifies the terminals of the completion of SIP registration. Then, the user receives a call using the same kind of a terminal as a specific terminal previously set on the basis of a user&#39;s preferences among the terminals in the specific region.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Korea Patent Application No. 2003-87886filed on Dec. 5, 2003 in the Korean Intellectual Property Office, thecontent of which is incorporated herein by reference.More than onereissue application has been filed for the reissue of U.S. Pat. No.7,292,561. The reissue applications are application Ser. No. 12/612,327,filed on Nov. 4, 2009 and issued as U.S. Pat. No. Re. 42,996 (Parentreissue application), continuation reissue application havingapplication Ser. No. 13/300,799, filed on Nov. 21, 2011 and issued asU.S. Pat. No. Re. 43,789, and the present continuation reissueapplication, filed on Oct. 11, 2012.

This continuation reissue application is a continuation reissueapplication of U.S. patent application Ser. No. 13/300,799, filed onNov. 21, 2011 and issued as U.S. Pat. No. Re. 43,789, which is acontinuation reissue application of U.S. patent application Ser. No.12/612,327, filed on Nov. 4, 2009 and issued on Dec. 6, 2011 as U.S.Pat. No. Re. 42,996, which is a reissue of U.S. Pat. No. 7,292,561,filed on Jun. 30, 2004 as U.S. patent application Ser. No. 10/882,604and issued on Nov. 6, 2007, and claims priority from and the benefit ofKorean Patent Application No. 10-2003-0087886, filed on Dec. 5, 2003,all of which are hereby incorporated by reference for all purposes as iffully set forth herein.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to an SIP-based user mobility providingapparatus and method using user location information obtained by asensing apparatus.

(b) Description of the Related Art

There are a variety of networks having different performances andapplications for communication services. Users are provided with thecommunication services using various kinds of terminals. With thedevelopment of wired and wireless communication techniques, the userswant to select communication infrastructures providing the communicationservices according to their preferences.

The development of wired and wireless communication networks and auser's desire for being provided with the communication serviceswhenever and wherever the user wants, creates a service environment inwhich various communication networks coexist in an arbitrary place. Inthis service environment, the user can use various network servicesdepending on a place where the user uses the services, a moving speed,the kind of information the user wants to use, a performance level, andcosts. Furthermore, a user terminal used for communications can havevarious forms and a choice of a terminal may affect a choice of acommunication network. The user has an inclination in utilization ofcommunication services in the aforementioned service environment.

A session initiation protocol (SIP) is a call signaling protocol of anapplication layer, which provides multimedia session initiation,exchange of session information, and cancellation of session. The SIPallows a user to be provided with communication services using a uniformresource identifier (URI) irrespective of a physical position of a useror a user terminal. That is, a service based on a user's preferences canbe provided by several service features in an SIP-based multimediaservice environment. Furthermore, services that allow a user to select acommunication terminal according to his/her taste are proposed. Forexample, a receiving terminal for the wired/wireless telephone, E-mail,facsimile, and SMS service can be chosen according to a conditiondesignated by a user. For this, an SIP service network has a separatedatabase that stores user's preferences using for initiation of acommunication session.

However, the above-described service can be provided only when the userhas a designated terminal or he/she is in a place where the terminalexists. That is, if an arbitrary user provides his/her preferences forservices to the SIP service network, a call is accomplished only whenthe user is located beside a terminal that is designated such that itreceives the call at the instant of time when someone attempts to makethe call.

Accordingly, there has been proposed a ubiquitous service by which userscan be provided with information or services they want in any placeusing various devices having a computing function that exist in anyspace. For the ubiquitous service, it is required to collect variouscontexts of users in order to conjecture psychological states andthoughts of the users and provide services they need.

To grasp the states of the users, various sensing apparatuses arerequired. There are various sensing apparatuses depending on kinds ofinformation the apparatuses should collect.

Current selective services based on a user's preferences are provideddepending on only preference information that has been designated by theuser. Thus, the information can designate a terminal for receiving acall only when a designated condition, such as a condition that ‘a callis received by a specific terminal at a specific time zone’ or acondition that ‘a call satisfying a specific condition is sent to voicemail’, is satisfied. However, the call does not arrive at acorresponding user when the user is not located near the terminal.

Furthermore, terminals to be used for services using the SIP must beregistered before a communication session is initiated. The SIPRegistration cannot be spontaneously carried out when there is no user'sintention. In particular, when many unspecified persons share oneterminal, it is impossible to conjecture users and carry out the SIPregistration. In the case of originating a call, the SIP registration isperformed at the instant of time when a user signifies his/her intentionto make a call using a terminal, such that he/she uses the terminal,clicks a button or a mouse, or uses a keyboard, and then a session isinitiated. In the case of terminating a call, however, when the SIPregistration has not been carried out by SIP user agent, any attempt toexecute a communication is not received. Thus, a terminating part cannotcarry out the SIP registration in time because the terminating partcannot be aware of the time when the terminating part is requested toreceive a call. When the terminating part uses his/her own terminal, theSIP registration can be performed when the terminal is turned on or theterminating part previously sets the SIP registration. However, whenmany persons share one terminal or a user uses an arbitrary terminal inan arbitrary place, the user should carry out the registration using theseveral terminals. This considerably restricts the communication serviceusing the SIP.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide an SIP-based usermobility providing apparatus and method for supporting user mobilitysuch that a user can receive a call in any place he/she exists using anarbitrary terminal existing in the place by using an SIP service networkand a sensing apparatus in an environment where a variety ofcommunication infrastructures coexist.

In one aspect of the present invention, an SIP-based user mobilityservice providing apparatus is connected to an SIP-based IP multimediaservice network in an environment where various communicationinfrastructures coexist, and transmits an SIP message to an SIP terminaland an SIP proxy server through a gateway to provide a mobile user withan SIP service.

The SIP-based user mobility service providing apparatus comprises asensing part that detects an event that the user enters a specificregion or goes out of the specific region, to grasp a position of theuser, and a sensing management module that receives information on theposition of the user in the specific region from the sensing part andcarries out SIP registration for several terminal existing in thespecific region in place of the user, to allow the user to receive acall using a specific terminal among the plurality of terminals.

The specific terminal has the same capability as that of a terminalselected on the basis of a predetermined terminal priority orderdepending on a user's preferences among the several terminals existingin the specific region.

The sensing part includes a marker that transmits specific informationin response to the user's position, and a receiver that receives thespecific information from the marker to detect the event that the userenters the specific region or goes out of the specific region andtransmits the detected information to the sensing management module. Thesensing management module can be mounted in the gateway or constructedin a separate machine having computing capability.

The sensing management module comprises an interface unit forcommunicating with the receiver of the sensing unit, the SIP proxyserver, the SIP terminal, and an operator terminal that manages thereceiver of the sensing unit and controls the sensing management unit;an information managing unit that manages the user information andinformation on the terminals in the specific region; and an SIP servicesupporting unit that carries out SIP registration for the severalterminals existing in the specific region and notification of thecompletion of SIP registration such that the user is provided with theSIP service.

The operator terminal determines a range of the specific region on thebasis of a marker detection allowable limit of the receiver. Inaddition, the operator terminal determines a marker monitoring period todetermine whether the user exists in the specific region.

The sensing management module further comprises a user authenticationunit that determines whether the user in the specific region uses theseveral terminals existing in the specific region and whether the usersubscribes to an SIP service provider. The sensing management modulefurther comprises a management information database for storing SIPregistration related information including the user information and theinformation on the terminals in the specific region.

The information managing unit comprises a user/marker mapping managerfor managing mapping information of an ID of the marker and a URI of theuser; a terminal information manager for managing the information on theterminals existing in the specific region; and an active user managerfor managing information of the user activation in the specific region;

The SIP service supporting unit comprises an SIP userregistration/cancellation proxy unit that generates an SIP registrationmessage for each of the several terminals in the specific regionaccording and transmits the SIP registration message to the SIP proxyserver to perform SIP registration; and an SIP userregistration/cancellation notifying unit that notifies the SIP terminalof the completion of SIP user registration when SIP registration hasbeen completed through the SIP user registration/cancellation proxyunit.

The interface unit comprises a sensing receiver interface that providesan interface for transmitting information on the result of the detectionof the event that the user enters the specific region or goes out of theregion from the sensing part to the sensing management module; an SIPproxy server interface that provides an interface for transmitting theSIP registration message for each of the terminals to the SIP proxyserver; an SIP terminal interface that provides an interface fortransmitting the SIP registration completion notification to the SIPterminal; and an operator interface that provides an interface foroperating and controlling the sensing management module by the operatorterminal.

The present invention also provides an SIP-based user mobility serviceproviding method using an SIP-based user mobility providing apparatusthat is connected to an SIP-based IP multimedia service network in anenvironment where various communication infrastructures coexist, andtransmits an SIP message to an SIP terminal and an SIP proxy serverthrough a gateway to provide a mobile user with an SIP service.

The SIP-based user mobility service providing method comprisesconverting each terminals existing in a specific region to an availablestate when a user who is authorized to use the SIP service enters thespecific region; and receiving a call using a specific terminal havingthe same capability as that of a terminal previously set on the basis ofa user's preferences among the plurality of terminals in the availablestate.

The SIP-based user mobility service providing method further comprisingperforming user authentication for determining whether the user isauthorized to use the terminals existing in the specific region andwhether the user is authorized to use the SIP service when the userenters the specific region before the converting the terminals existingin the specific region to the available state when the user who isauthorized to use the SIP service enters the specific region.

The converting the each terminals existing in the specific region to theavailable state when the user who is authorized to use the SIP serviceenters the specific region comprises detecting the event that the userenters the specific region; generating an SIP registration message forthe each terminals in the specific region and transmitting the SIPregistration message to the SIP proxy server to carry out SIPregistration; and notifying the SIP terminal of the completion of SIPregistration when SIP registration has been completed.

The converting the each terminals existing in the specific region to theavailable state when the user who is authorized to use the SIP serviceenters the specific region further comprises periodically confirmingwhether the user exists in the specific region after the notifying theSIP terminal of the completion of SIP registration when SIP registrationhas been completed.

The converting the each terminals existing in the specific region to theavailable state when the user who is authorized to use the SIP serviceenters the specific region further comprises, when it is confirmed thatthe user does not exist in the specific region, generating an SIPregistration cancellation message for the plurality of terminals in thespecific region and transmitting the SIP registration cancellationmessage to the SIP proxy server, to carry out cancellation of SIPregistration; and notifying the SIP terminal of the completion of SIPregistration cancellation when the cancellation of SIP registration hasbeen completed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate an embodiment of the invention,and. together with the description, serve to explain the principles ofthe invention:

FIG. 1 illustrates a service environment where various communicationnetworks coexist, to which the present invention is applied;

FIG. 2 illustrates a mobile multimedia service environment forsupporting user mobility according to an embodiment of the presentinvention;

FIG. 3 illustrates an SIP-based mobile multimedia service network inconnection with a sensing apparatus according to an embodiment of thepresent invention;

FIG. 4 is a block diagram of a sensor management module of an SIP-baseduser mobility providing apparatus according to an embodiment of thepresent invention; and

FIG. 5 is a flow chart illustrating an SIP-based user mobility providingmethod according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description, only the preferred embodiment ofthe invention has been shown and described, simply by way ofillustration of the best mode contemplated by the inventor(s) ofcarrying out the invention. As will be realized, the invention iscapable of modification in various obvious respects, all withoutdeparting from the invention. Accordingly, the drawings and descriptionare to be regarded as illustrative in nature, and not restrictive.

FIG. 1 illustrates a service environment where a variety ofcommunication networks coexist, to which the present invention isapplied.

As shown in FIG. 1, the service environment 100 includes a wireless LAN(WLAN) environment 101 having access points which are equipped in acampus or an office building, which is used for walking speed; acellular or personal mobile communication environment 102 usable for amoving speed higher than a certain level, such as in a car; a Bluetoothenvironment 103 for communications through radio apparatuses or Internetaccess in the home or office; a conventional fixed network environment104; and any other network environments 105.

The above-described communication infrastructures provide communicationservices while being overlapped in an arbitrary region, and they can beclassified depending on a method of providing a physical communicationpath. Furthermore, the communication infrastructures can includenetworks of different telecommunication operators using the samecommunication method. Users select communication infrastructures orterminals used for communications on the basis of various and complicatefactors including costs, environmental factors, personal tastes, and soon. For example, the users can select communication infrastructures orterminals on the basis of capability of currently usable terminals, abilling policy of a communication infrastructure, service quality,importance of a communication counterpart, an emergency degree, and soon. These factors are combined with information on a specific time zoneor a place where the users exist, and are applied to the selection ofthe communication infrastructures or terminals.

A system and a method for providing user mobility in a ubiquitousenvironment will now be explained.

FIG. 2 illustrates a mobile multimedia service environment forsupporting user mobility according to an embodiment of the presentinvention. FIG. 2 shows a mobile multimedia service environmentsupporting user mobility, to which a moving user's preferences can beapplied, in an environment where various communication infrastructurescoexist.

The mobile multimedia service environment for supporting user mobilityincludes an SIP service network 200 that provides a mobile multimediaservice using an SIP on the basis of various communicationinfrastructures 100 having different transmission methods.

The environment having the various communication infrastructuresincludes a service environment having a sensing region 300 where a userwho has been moved from a region where his/her terminal exists to thesensing region 300 can originate or terminate a call using a terminalexisting in the sensing region. In the sensing region 300, communicationservices are provided to the user through a terminal resource existingin the area where the user is located on the basis of a user'spreferences previously registered without having the user's intentionalintervention in cooperation with the SIP service network 200 that is aservice control network. FIG. 3 illustrates the SIP service network(SIP-based mobile multimedia service network) in connection with asensing apparatus in the sensing region according to an embodiment ofthe present invention.

According to the present invention, the sensing apparatus 310 isinstalled in the sensing region 300 in order for the SIP service network200 to support user mobility. The sensing apparatus 310 manages thesensing region 300 and includes a receiver 312 and markers 314. Variouskinds of sensing apparatuses can be utilized depending on a sensingmethod and physical structural characteristics of an environment wherethe sensing apparatus is installed.

The sensing region 300 is a space where an arbitrary user selects one ofterminals 320 existing therein to use the selected terminal forcommunications. The sensing region 300 is formed by installing thesensing apparatus and defining a sensing diameter.

Furthermore, the sensing region 300 means an area where the receiver 312can recognize signals of the markers 314. The range of the sensingregion 300 can be varied according to a selected sensing apparatus. Thesensing region 300 can be intentionally formed to be small or large inorder to define a personal space within the capability of the sensingapparatus 310.

Each of the markers 314 transmits unique information such as an ID tothe receiver 312 such that the receiver 312 knows the existence of themarker 314. The marker 314 has a small size and low power consumptionsuch that a user uses it conveniently. The user should carry the marker314. The receiver 312 receives the ID of the marker 314 using apredetermined method to detect a movement of the user carrying themarker 314.

The SIP service network 200 includes an SIP proxy server 210, an SIPregistration server 220, an SIP redirect server 230, an SIP presenceserver 240, and an SIP application server 250. The SIP service network200 uses functions of a conventional SIP service network so thatdetailed explanation thereof is omitted.

To transmit information on the movement of the user who carries themarker 314 to the SIP service network 200, which is obtained from theidentification of the marker 314 by the receiver 312, a sensingmanagement module having sensing management and transmission functionsof storing or processing the user movement information is required.

FIG. 4 is a block diagram of the sensing management module of theSIP-based user mobility providing apparatus according to an embodimentof the present invention. Here, the sensing management module is mountedin a gateway 330 (shown in FIG. 3).

Referring to FIG. 4, the sensing management module 400 includes aninterface unit 410, an information management unit 420, a managementinformation database 430, a user authentication unit 440, and an SIPservice supporting unit 450. The interface unit 410 includes a sensingreceiver interface 412, an SIP proxy server interface 414, an SIPterminal interface 416, and an operator interface 418.

The sensing receiver interface 412 receives the identifier of the marker314 whose movement is recognized. In addition, the sensing receiverinterface 412 depends on a hardware connection of the receiver 312 andthe computer (gateway) 330 in order to obtain information on a user whoenters a corresponding region.

The SIP proxy server interface 414 is connected with an SIP userregistration/cancellation proxy unit 452 to transmit/receive an SIPmessage to/from the SIP proxy server 210. The SIP terminal interface 416is connected with an SIP user registration/cancellation notifying unit454 to enable communication between the SIP terminal 320 and thecomputer (gateway) 330 on the basis of a communication method of the SIPterminal 320 existing in the sensing region 300 and the gateway 330. Thecommunication method is determined on the basis of a wired or wirelesscommunication standard or mode. Accordingly, the SIP terminal interface416 is operated on the basis of information required for the interface416 to be connected with the SIP terminal 320. This information can bestored in the management information database 430 and managed by it.

The operator interface 418 interfaces an operator terminal 270, theinformation management unit 420, and the SIP service supporting unit 450with one another to allow an operator to search or change parameters fora rule that the operator should observe when he/she controlsenvironmental variables, adds or deletes information, and carries outreal-time operation though the operator terminal 270.

The operator terminal 270 controls reference values for proceduresprocessed by various data tables and the components of the sensingmanagement module 400 while the sensing management module 400 isoperated. Furthermore, the operator terminal 270 determines a range ofthe sensing region 300 where the sensing apparatus 310 is installed toprovide the service. In addition, the operator terminal 270 determines amonitoring period of the marker 314 for confirming whether a usercontinuously exists in the corresponding sensing region 300.

The information management unit 420 includes a user/marker mappingmanager 422, a terminal information manager 424, and an active usermanager 407. The user/marker mapping manager 422 maps the ID of themarker 314 with a URI that means a specific user when the sensingapparatus 310 receives the Identifier of the marker 314. The user/markermapping manager 422 is operated by a table that manages mapping of themarker ID and the user URI. The table is stored in the separate database430 and managed by the database.

In the case that there are multiple sensing regions and users want to beprovided with user mobility service while moving in these sensingregions, all information on mapping between the users and markers can bestored in sensing management modules corresponding to the respectivesensing regions when the number of the users is small. When the numberof the users is not small, a separate database can be used. Here, thesensor management module 400 can have a function of executing a separatecommunication with the separate database in order to obtain a URI of auser having a specific marker ID.

The terminal information manager 424 manages information on terminalsexisting in a specific region. Here, the information on the terminalsincludes information on characteristics of each terminal, which isrequired for the SIP service supporting unit 450 to carry out SIPregistration in place of a user agent UA of the terminal, andinformation required for the user agent UA to perform SIP registrationin the SIP service network 200. The information on the terminals isstored in the separate database 430.

The active user manager 426 manages active information on whether a userexists in the corresponding sensing region 300. In addition, the activeuser manager 426 manages information on active users through thedatabase 430.

The user authentication unit 440 authenticates whether a user who hasmoved to the corresponding sensing region 300 is authorized to use theterminals 320 existing in the sensing region or to use the mobilemultimedia service. Information required for the authentication isstored in the database 430 and managed by the database 430. The userauthentication unit 440 can be operated by a separate authenticationserver such that multiple sensing regions can commonly access the userauthentication unit 440.

The SIP service supporting unit 450 includes the SIP userregistration/cancellation proxy unit 452 and the SIP userregistration/cancellation notifying unit 454. The SIP userregistration/cancellation proxy unit 452 carries out SIP registrationfor a corresponding user in place of user agents of the SIP terminals.

The SIP user registration/cancellation notifying unit 454 notifies theuser agents of the SIP terminals that SIP user registration has beencompleted when the gateway finishes SIP registration. Here, informationrequired for operating a service session for a corresponding SIPterminal is transmitted.

The sensing management module 400 constructed as above carries out SIPregistration of a corresponding terminal in place of a user such thatthe user can be provided with the SIP service using the terminal in aspecific region. By doing so, the sensing management module 400 canmanage the terminals existing in the sensing region 300 in order toselect a terminal used for a communication session on the basis of apredetermined user's preferences in a specific region, and to controlthe terminals to be available when the user enters the sensing region300.

An SIP-based user mobility providing method using user positioninformation obtained by the sensing apparatus will now be explained indetail with reference to FIG. 5. FIG. 5 is a flow chart showing theSIP-based user mobility providing method according to an embodiment ofthe present invention.

When a user enters the sensing region 300, the receiver 312 receives theID of the marker 314 using a predetermined method to detect a movementof the user in step S502. For example, the receiver 312 carries out aseparate procedure of confirming the existence of the marker 314periodically to detect a movement of a person or an object carrying themarker 314 when the marker 314 is passive. When the marker 314 isactive, the receiver 312 detects a movement of the person or objectcarrying the marker 314 through information received from the marker314.

The receiver 312 that has detected a motion of the user transmits the IDof the marker to the sensing management module 400 through the receiverinterface 412. That is, the receiver 312 recognizes whether the userenters a specific area defined as the sensing region 300 or goes out ofthe area in step S502, and controls information on the marker 314 andprocesses the received identification information of the marker totransmit it to the gateway in step 504, to support user mobility.

Then, the user/marker mapping manager 422 of the sensing managementmodule 400 maps the marker ID with a URI of the user to determine thatthe user has entered the sensing region 300 in step S506. Mappinginformation on the marker ID and user's URI is managed by acorresponding service provider when the user subscribes to the serviceprovider to be provided with the marker. That is, the mappinginformation on all users who can be provided with the service in thesensing region 300 is managed irrespective of whether the users exist inthe sensing region.

When the existence of the marker is recognized through the sensingreceiver interface 412, the user authentication unit 440 of the sensingmanagement module 400 determines whether the user carrying the marker isauthorized to use a terminal existing in the sensing region 300 toauthenticate the user in step S508.

When it is confirmed that the user entering the sensing region 300subscribes to an SIP service provider, the SIP userregistration/cancellation proxy unit 452 of the sensing managementmodule 400 generates an SIP registration message in place of a useragent UA of each terminal 320 existing in the sensing region 300 in stepS510, and transmits the SIP registration message to the SIP proxy server210 through the SIP proxy server interface 414 in step S512. When theSIP proxy server 210 receives the SIP registration message from the SIPuser registration/cancellation proxy unit 452, the SIP proxy server 210transmits an acknowledge signal SIP OK in response to the receivedresult in step S514.

At the instant of time when the sensing management module 400 completesthe SIP registration, the SIP user registration/cancellation notifyingunit 454 of the sensing management module 400 generates SIP registrationcompletion messages for all of the SIP terminals existing in the sensingregion 300 in step S516, and notifies the user agents of the SIPterminals that the SIP user registration has been completed in stepS518. When each of the SIP terminals receives the notification, ittransmits an acknowledge signal to the sensing management module 400 instep S520. Then, the user agent UA of each SIP terminal becomes anavailable state for transmitting or receiving an INVITE message capableof carrying out the service after SIP registration is finished.

The sensing management module 400 periodically sends a confirmationsignal to the receiver 312 with respect to the user existing in thesensing region 300 to confirm whether the marker IDs recognized by thereceiver 312 still exist in step S522. The receiver 312 that hasreceived the 15 confirmation signal from the sensing management module400 transmits IDs of markers existing in the sensing region 300. Whenthere is no ID of the marker that previously entered the sensing region300 among the marker IDs transmitted from the receiver, a user carryingthe corresponding marker is considered to have gone out of the sensingregion 300. These operations are performed by the active user manager426.

When the active user manager 426 of the sensing management module 400determines that the corresponding user has gone out of the sensingregion 300 in step S525, the SIP user registration/cancellation proxyunit 452 generates an SIP deregistration message in step S526, to cancelthe SIP registration for the corresponding SIP terminal 320. Then, theSIP user registration/cancellation proxy unit 452 transmits the SIPderegistration message to the SIP proxy server 210 through the SIP proxyinterface 414 in step S528. The SIP proxy server 210 receives the SIPderegistration message and transmits an acknowledge signal SIP OK to thesensing management module 400 in step S530.

At the instant of time when the sensing management module 400 completesthe cancellation of SIP registration, the SIP userregistration/cancellation notifying unit 454 of the sensing managementmodule 400 generates an SIP deregistration completion message for allthe SIP terminals existing in the sensing region 300 in step S532, tonotify the user agents UA of the SIP terminals that the SIPderegistration has been cancelled in step S534. Each the SIP terminalsthat has received the notification transmits an acknowledgement signalACK to the sensing management module 400 in step S536.

While the separate computer (gateway) 330 having software functioning asthe sensing management module is connected with the sensing apparatus310 in the aforementioned embodiment of the present invention, it is notrestricted thereto. For example, the sensing apparatus 310 may not beconnected to the gateway 330 and the receiver 312 of the sensingapparatus 310 may be constructed such that it has computing capability.Otherwise, the sensing management module can be inserted into a separatedevice having computing capability and being operated through aninternal interface of the sensing apparatus 310.

The components of the sensing management module are required to managean arbitrary sensing region. When a management region of a gatewayexisting for a specific purpose on a home network or an office networkor agents, which are included in a physical network environment havingunique characteristics, corresponds to the sensing region, thecomponents of the sensing management module can be mounted on the sameplatform as the platform of the gateway or agents.

While this invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment,it is to be understood that the invention is not limited to thedisclosed embodiments, but, on the contrary, is intended to covervarious modifications and equivalent arrangements included within thespirit and scope of the appended claims.

According to the present invention, a user can use a terminal existingin an arbitrary area to originate a call or receive a call when the userhas moved to the area from an area where his/her terminal exists in anenvironment where various communication terminals and communicationinfrastructures for supporting the terminals coexist. Furthermore, evenwhen the user is located in an area where his/her terminal does notexist, the user can be provided with a desired communication serviceusing a terminal having the same capability and characteristics as thoseof his/her terminal if the terminal exists in the area.

Moreover, the present invention can support user mobility such that auser can be provided with the user mobility services using variousterminals. Furthermore, according to the present invention, the userdoes not have to intentionally carry out SIP user registration using aterminal he/she wants to use. In addition, since an arbitrary terminalcan provide a ubiquitous service for an arbitrary user in a ubiquitousservice environment, the user can receive a call using the same kind ofterminal as his/her own terminal among terminals existing in the areawhere the user is currently located.

What is claimed is:
 1. An SIP (Session Initiation protocol)-based usermobility service providing apparatus that is connected to an SIP-basedIP multimedia service network in an environment where variouscommunication infrastructures coexist and transmits an SIP message to anSIP terminal and an SIP proxy server through a gateway to provide amobile user with an SIP service, comprising: a sensing part that detectsan event that the user enters a specific region or goes out of thespecific region based on signals from at least one marker, to obtain aposition of the user; and a sensing management module that receivesinformation on the position of the user in the specific region from thesensing part and carries out SIP registration for terminals in thespecific region when it is confirmed that the user, enters the specificregion and carries out SIP cancellation of SIP registration forterminals in the specific region when it is confirmed that the user goesout of the specific region.
 2. The SIP-based user mobility serviceproviding apparatus as claimed in claim 1, wherein the specific terminalhas the same capability as that of a terminal selected on the basis of apredetermined terminal priority order depending on a user's preferencesamong the several of terminals existing in the specific region.
 3. TheSIP-based user mobility service providing apparatus as claimed in claim1, wherein the at least one marker transmits specific information in thesignals in response to the user's position, and the sensing partincludes a receiver that receives signals with the specific informationfrom the at least one marker to detect the event that the user entersthe specific region or goes out of the specific region and transmits thedetected information to the sensing management unit.
 4. The SIP-baseduser mobility service providing apparatus as claimed in claim 1, whereinthe sensing management module is mounted in the gateway.
 5. TheSIP-based user mobility service providing apparatus as claimed in claim1, wherein the sensing management module is constructed in a separatemachine having computing capability.
 6. The SIP-based user mobilityservice providing apparatus as claimed in claim 1, wherein the sensingmanagement module comprises: an interface unit for communicating withthe receiver of the sensing unit, the SIP proxy server, the SIPterminal, and an operator terminal that manages the receiver of thesensing unit and controls the sensing management unit; an informationmanaging unit that manages the user information and information on theterminals in the specific region; and an SIP service supporting unitthat carries out SIP registration for the each terminals existing in thespecific region and notification of the completion of SIP registrationsuch that the user is provided with the SIP service.
 7. The SIP-baseduser mobility service providing apparatus as claimed in claim 6, whereinthe operator terminal determines a range of the specific region on thebasis of a marker detection allowable limit of the receiver.
 8. TheSIP-based user mobility service providing apparatus as claimed in claim6, wherein the operator terminal determines a marker monitoring periodto determine whether the user exists in the specific region.
 9. TheSIP-based user mobility service providing apparatus as claimed in claim6, wherein the sensing management module further comprises a userauthentication unit that determines whether the user in the specificregion uses the several terminals existing in the specific region andwhether the user subscribes to an SIP service provider.
 10. TheSIP-based user mobility service providing apparatus as claimed in claim6, wherein the sensing management module further comprises a managementinformation database for storing SIP registration related informationincluding the user information and the information on the terminals inthe specific region.
 11. The SIP-based user mobility service providingapparatus as claimed in claim 6, wherein the information managing unitcomprises: a user/marker mapping manager for managing mappinginformation of an ID of the at least one marker and a URI (uniformresource identifier) of the user; a terminal information manager formanaging the information on the terminals existing in the specificregion; and an active user manager for managing active information ofthe user in the specific region.
 12. The SIP-based user mobility serviceproviding apparatus as claimed in claim 6, wherein the SIP servicesupporting unit comprises: an SIP user registration/cancellation proxyunit that generates an SIP registration message for each of the severalterminals in the specific region according to the SIP registrationrelated information and transmits the SIP registration message to theSIP proxy server to perform SIP registration; and an SIP userregistration/cancellation notifying unit that notifies the SIP terminalof the completion of SIP user registration when SIP registration hasbeen completed through the SIP user registration/cancellation proxyunit.
 13. The SIP-based user mobility service providing apparatus asclaimed in claim 6, wherein the interface unit comprises: a sensingreceiver interface that provides an interface for transmittinginformation on the result of the detection of the event that the userenters the specific region or goes out of the region from the sensingpart to the sensing management module; an SIP proxy server interfacethat provides an interface for transmitting the SIP registration messagefor each of the terminals to the SIP proxy server; an SIP terminalinterface that provides an interface for transmitting the SIPregistration completion notification to the SIP terminal; and anoperator interface that provides an interface for operating andcontrolling the sensing management module by the operator terminal. 14.An SIP-based user mobility service providing method using an SIP(session initiation protocol)-based user mobility providing apparatusthat is connected to an SIP-based IP multimedia service network in anenvironment where various communication infrastructures coexist, andtransmits an SIP message to an SIP terminal and an SIP proxy serverthrough a gateway to provide a mobile user with an SIP service,comprising: a) converting each terminals existing in a specific regionto an available state when a user who is authorized to use the SIPservice enters the specific region; and b) receiving a call using aspecific terminal having the same capability as that of a terminalpreviously set on the basis of a user's preferences among the severalterminals in the available state, wherein converting each terminalfurther comprises: detecting an event that the user enters the specificregion based on signals from at least one marker; generating an SIPregistration message for terminals in the specific region andtransmitting the SIP registration message to the SIP proxy server tocarry out SIP registration when it is confirmed that the user enters thespecific region; and generating an SIP deregistration message for theterminals in the specific region and transmitting the SIP deregistrationmessage to the SIP proxy server, to carry out cancellation of SIPregistration when it is confirmed that the user goes out of the specificregion.
 15. The SIP-based user mobility service providing method asclaimed in claim 14, further comprising performing user authenticationfor determining whether the user is authorized to use the terminalsexisting in the specific region and whether the user is authorized touse the SIP service when the user enters the specific region before theconverting the each terminals existing in the specific region to theavailable state when the user who is authorized to use the SIP serviceenters the specific region.
 16. The SIP-based user mobility serviceproviding method as claimed in claim 15, wherein step a) furthercomprises periodically confirming whether the user exists in thespecific region after the notifying the SIP terminal of the completionof SIP registration when SIP registration has been completed.
 17. An SIP(Session Initiation Protocol)-based user mobility service providingapparatus that is connected to an SIP-based IP multimedia servicenetwork, comprising: a receiver to receive a signal from a portabledevice to detect that the portable device enters a specific region orgoes out of the specific region; and a management unit to receiveinformation related to the portable device based on the signal, and tocarry out registration using a first SIP message for a terminal in thespecific region when the portable device enters the specific region, andto carry out deregistration using a second SIP message for the terminalin the specific region when the portable device goes out of the specificregion.
 18. The SIP-based user mobility service providing apparatus asclaimed in claim 17, wherein the specific region is determined on thebasis of an area where the receiver recognizes the signal from theportable device.
 19. The SIP-based user mobility service providingapparatus as claimed in claim 17, wherein the portable device has asmall size and low power consumption.
 20. The SIP-based user mobilityservice providing apparatus as claimed in claim 17, wherein themanagement unit selects the terminal for a communication session. 21.The SIP-based user mobility service providing apparatus as claimed inclaim 17, wherein the management unit comprises: an interface unit tocommunicate with the receiver, an SIP proxy server, the terminal, and anoperator terminal that manages the receiver and controls the managementunit; an information managing unit to manage user information andinformation on the terminal in the specific region; and an SIP servicesupporting unit to carry out the registration for the terminal in thespecific region and notification of the completion of the registration.22. The SIP-based user mobility service providing apparatus as claimedin claim 21, wherein the operator terminal determines a range of thespecific region on the basis of an area where the receiver recognizesthe signal from the portable device.
 23. The SIP-based user mobilityservice providing apparatus as claimed in claim 21, wherein themanagement unit further comprises a user authentication unit todetermine whether a user corresponding to the portable device isauthorized to use the terminal in the specific region.
 24. The SIP-baseduser mobility service providing apparatus as claimed in claim 21,wherein the management unit further comprises a management informationdatabase to store registration related information including the userinformation and the information on the terminal in the specific region.25. The SIP-based user mobility service providing apparatus as claimedin claim 21, wherein the information managing unit comprises: auser/portable device mapping manager to map specific information of theportable device with a URI (uniform resource identifier) of a user; aterminal information manager to manage the information on the terminalin the specific region; and an active user manager to manage activeinformation of the user in the specific region.
 26. The SIP-based usermobility service providing apparatus as claimed in claim 21, wherein theSIP service supporting unit comprises: an SIP userregistration/cancellation proxy unit to generate the first SIP messagefor the registration of the terminal in the specific region according tothe registration related information and to transmit the first SIPmessage for the registration to the SIP proxy server to perform theregistration; and an SIP user registration/cancellation notifying unitto notify the terminal of the completion of the registration when theregistration has been completed through the SIP userregistration/cancellation proxy unit.
 27. The SIP-based user mobilityservice providing apparatus as claimed in claim 21, wherein theinterface unit comprises: a sensing receiver interface to provide aninterface for transmitting information, when the portable device entersthe specific region or goes out of the region, from the receiver to themanagement unit; an SIP proxy server interface to provide an interfacefor transmitting the first SIP message for the registration of theterminal to the SIP proxy server; an SIP terminal interface to providean interface for transmitting the registration completion notificationto the terminal; and an operator interface to provide an interface foroperating and controlling the management unit by the operator terminal.28. An SIP-based user mobility service providing method using an SIP(session initiation protocol)-based user mobility providing apparatusthat is connected to an SIP-based IP multimedia service network,comprising: receiving a signal from a portable device at a receiver todetect that the portable device enters a specific region or goes out ofthe specific region; receiving information related to the portabledevice based on the signal from the receiver at a management unit; andperforming, by the management unit, registration using a first SIPmessage for a terminal in the specific region when the portable deviceenters the specific region; wherein the management unit performsderegistration using a second SIP message for the terminal in thespecific region when the portable device goes out of the specificregion.
 29. The SIP-based user mobility service providing method asclaimed in claim 28, wherein the specific region is determined on thebasis of an area where the receiver recognizes the signal from theportable device.
 30. The SIP-based user mobility service providingmethod as claimed in claim 28, wherein the portable device has a smallsize and low power consumption.
 31. The SIP-based user mobility serviceproviding method as claimed in claim 28, wherein the management unitselects the terminal for a communication session.
 32. The SIP-based usermobility service providing method as claimed in claim 28, wherein themanagement unit determines whether a user corresponding to the portabledevice is authorized to use the terminal in the specific region.
 33. AnSIP-based user mobility service providing method using an SIP (sessioninitiation protocol)-based user mobility providing apparatus that isconnected to an SIP-based IP multimedia service network, comprising:converting a terminal in a specific region to an available state or anunavailable state on the basis of a detection that a portable deviceenters the specific region or exits the specific region; and receiving acall using the terminal for a communication session, wherein convertingthe terminal to the available state further comprises: detecting thatthe portable device enters the specific region based on a signal fromthe portable device; generating a first SIP message for registration ofthe terminal in the specific region and transmitting the first SIPmessage to an SIP proxy server to carry out the registration if theportable device enters the specific region; wherein converting theterminal to the unavailable state further comprises: detecting that theportable device exits the specific region based on a signal from theportable device; generating a second SIP message for deregistration ofthe terminal in the specific region and transmitting the second SIPmessage for deregistration to the SIP proxy server to carry outderegistration if the portable device exits the specific region.
 34. TheSIP-based user mobility service providing method as claimed in claim 33,wherein the specific region is determined on the basis of an area wherethe receiver recognizes the signal from the portable device.
 35. TheSIP-based user mobility service providing method as claimed in claim 33,wherein the portable device has a small size and low power consumption.36. The SIP-based user mobility service providing method as claimed inclaim 33, further comprising: performing user authentication fordetermining whether a user corresponding to the portable device isauthorized to use the terminal in the specific region when the userenters the specific region before the converting the terminal in thespecific region to the available state.